To get the most information about what ports are open, what state they're in, and other relevant network information, I would suggest you download nmap. It's a free network mapper/port scanner, and by typing either nmap -v 127.0.0.1 in Command Prompt or 127.0.0.1 in the "Host" or "Target" field in the GUI counterpart (called Zenmap), you will quickly obtain any information you need about open ports on your computer.